Automatic control mechanism for drilling rigs



March 5, 1929. DETWILER 1,704,464

AUTOMATIC CONTROL MECHANISM FOR DRILLING RIGS Filed April 13. 1927 5Sheets-Sheet 1 A TTORN x March 5, 1929. F. M. DETWILER AUTOIATIC CONTROLMECHANISM FOR DRILLING RIGS Filed April 13, 1927 5 Sheets-Sheet 2 March5, 1929. F. M. DETWILER AUTOIATIC CONTROL MECHANISM FOR DRILLING RIGSFiled April 13, 1927 3 Sheets-Sheet INVENTOR %l0 ud M. Uefwz'ler ATTORNE Y Patented- Mar. 5, 1929.

UNITED STATES PATENT OFFICE.

Application fled April 13, 1927. Serial No. 163,568.

My invention relates to well drilling rigs and has for it's purpose theprovision of a mechanism capable of being readily applied to thestandard drillingrig and operating automatically to discontinueoperation of the prime mover, whether it be a steam or gas um of asecond upright 32 likewise provided with a flange base 33 secured to thebelt house floor. The upper ends of the uprights 30 and 32 are formeintegral with a transverse tubular member 34, one end of which isprovided with a disk-shaped head 35 secured to engine, immediately uponthe belt becoming --a vertical partition of the belt house. A

untrained from the band wheel, or breaking of a pump rod, drill rod,wrist pin, or any other moving part of the rig which will permit racingof the prime mover and consequent injury to the rig and prime mover.

I will describe only one form of automatic control mechanism fordrilling rigs, and will point out the novel features thereofin claims.

In the accompanying drawings, 7

Figure 1 is a viewshowing in side elevation one form of automaticcontrol mechamsm in applied position to a drilling rig, the housing forthe rig being shown in section;

Figure 2 is an enlarged fragmentary view showing in side elevation thedrilling rig and control mechanism, the latter bein shown in a positionabout to be tripped to iscontinue operation of the prime mover;

Figure 3 is a vertical sectional view taken on the line 3-3 of Figure 1;

Figure 4 is a plan view of the drilling rig and mechanism shown inFigure 2 Figure 5 is a horizontal sectional view taken on the line 55 ofFigure 3.

Referring specifically to the drawin I have illustrated a standard formof dri ing rig which will include a prime mover P, in the presentinstance a steam engine, to which steam is supplied by a pipe 15 havinginterposed therein a throttle valve 16 rovide'd with an operating arm17. The engine shaft 18 is povided with a wheel 19 about which istrained a belt 20, the latter being also trained about a band wheel 21to rotate the latter in the direction of the arrow in Figure 2. The bandwheel shaft 22 carries a crankv23 rovided with awrist pin 24 which worksin a slot 25 of a pitman 26 operatively connected to one end of awalking beam 27. Of course, the opposite end of the walking beam isoperatively connected to the pump rod or drill rod 28 as the case maybe,- which extends down into the well.-

The automatic control mechanism embodying my invention comprises, in thepresent instance, a tubular upright 30 having a flanged lower end 31bolted or otherwise secured to the floor of the belt house. This uprightis rigidly braced through the mediweight 36 is slidable on the'upri'ght30 and 1S operatively connected tothe throttle valve arm 17 by a cable37 trained over a pulley 38 secured on the upright 30. This weight 36normall acts to swing the valve arm 17 t0 the dotted in e position shownin Figure 2, in which position the throttle valve is closed todiscontinue the supply of steam'to the en e P. Normally, however, theweight 3 is latched 1n elevatedposition to prevent movement of thethrottle valve to closed position by means of a latch lever 39 having abill 40 wh ch engages within an eye41 secured to the weight 36. Thislever is fulcrumed on the stem 30 and its fulcrum oint may be adjustedvertically on the standard by the rovision of a lurahty of openings 42throng any one of w ich a pivot pin or bolt 43 may extend. The latchlever 39 is made'of two sections adjustably connected by the provisionof a plurality of openings 43 and bolts 44 for the purpose of allowinthe lever to be lengthened or shortened, as will be more fully describedhereinafter.

As shown in Figure 5, the free end of the lever 39 is flattened and asshown in Figure 2 it is adapted to be engaged by the u per end of a bellcrank lever 45 fulcrum on the pitman 26 at a point above the slot 25.Pivoted at 45 on the lever 45 is an arm 45 which depends from the leverand is adjustable to dispose its lower end in the path of movement ofthe wrist pin 24, dependence bein laced on friction at the pivotalmounting o tl i e arm to maintain it in the position relative to thelever 45, to which it is adjusted. The norinal position of the lever45in which it clears the end of the lever 39 is shown in Fig. 1, andduring the normal operation of the drilling rig the wrist pin 24 is atall times maintained at the lower end of. the slot 25 of the pitman 26due to the weight of the pump or drill rod constantly acting to rock theleft hand end of the walking beam 24'upwardly as viewed in Figs. 1 and 2and hence constantly exert an upward pull upon the pitman. However,should the pump or drill rod break and thus relieve from the walkingbeam the load normally imposed thereon, the wrist pin 24 will be free tomove upwardly in the slot 25 to engage and thus move the lever 45 totripping position shown in Fig. 2, so that with continued rotation ofthe band wheel the lever will engage the latch lever 39 and elevate thelatter to release the weight 36, thereby discontinuingoperation of theengine P.

The lever 45 constitutes only one means by which the latch lever 39 canbe tripped to release the weight 36 and thus move the throttle valve 16to closed position to discontinue operation of the engine P. Anothermeans for actuating the lever 39 is a lever 47 fulcrumed in a bearing 48secured to the standard 32 and including a lower arm 49 disposed belowthe upper stretch of the belt 20, and an upper arm 50 disposed beneaththe lever 39. By this arrangement, it will be seen that should the belt20 become untrained with respect to the band wheel 21 its upper stretchwill fall and engage the arm 49, thus elevating the arm 50 sutticientlyto trip the latch lever 39 and thereby release the weight 36. lVithfalling of the weight 36, the throttle valve 16 will be moved to closedposition to discontinue operation of the engine P.

Should the connection between the walking beam 27 and the band wheelshaft 22 for any reason break, the weight of the pump rod or otherdevice which the walking beam is actuating will throw the pitman endotthe walking beam upwardly to such a height as to actuate a cable 51connected to the walking beam and to the latch lever 39, as shown inFigure 2, to elevate the latch lever and release the weight 36, therebyeffecting discontinuance in operation of the engine P. The length ofthis cable 51 is such that during thenormal operation of the walkingbeam there is suflicient slack provided in the cable to prevent trippingof the lever 39, thus preventing accidental tripping of the lever, aswill be understood.

From the foregoing description, it will be manifest that I have providedan automatic control mechanism for drilling rigs which embodies veriousmeans for effecting discontinuance in operation of the prime mover whenvarious movable parts of the rig fail to perform their intendedfunctions, or when the pump rod or other rod which the walking beam isactuating breaks. It will be understood that any failures in the rigmechanism will permit racing of the prime mover and any parts of the rigwhich remain connected with the prime mover, thus causing injury tothese parts as well as the prime mover. By the provision of my automaticcontrol mechanism, operation of the prime mover is immediatelydiscontinued under any of these conditions, thereby preventing injury tothe prime mover and the parts 01'' the rig.

By making the latch lever 39 adjustable, its free end can be positionedat the proper point to be engaged by the bell crank lever 45 when moter.-

the latter is moved to active position against the stop 46 andirrespective of the adjustment of the wrist pin 24: with respect to thecrank 23, it being understood that in the operation of drilling rigs itis necessary to change the stroke of the walking beam through anadjustment of the wrist pin on the crank. It will thus be seen thatirrespective of the stroke of the pitman my control mechanism can bemade to operate through an adjustment of the latch lever 39.

Although I have herein shown and described only one form of controlmechanism for drilling rigs embodying my invention, it is to beunderstood that various changes and modifications may be made thereinwithout departing from the spirit of the invention and the spirit andscope of the appended claims.

I claim as my invention: v

1. An automatic control mechanism for well rigs comprising a Weightadapted for operative connection to the control element of a prime moverand adapted to actuate the control element to discontinue operation ofthe prime mover when the weight is released, means for latching theweight in an elc ated position to prevent operation of the controlelement, and means adapted for operation by the pitman of the well rigfor actuating the latching means to release the weight, the last meansnormally occupying a position in which it is ineffective to actuate thelatching means, said means in this position adapted to be engaged by awrist pin of the rig to move said means to the first mentioned position.

2. An automatic control mechanism for well rigs comprising an upright, aweight movable on the upright, a cable connected to the weight andadapted for connection to the throttle valve of an engine, a latch leverfulcrumed on the upright and normally holding the weight in elevatedposition to prevent actuation of the throttle valve, a bell crank leveradapted for mounting on a pitman to occupy either of two positons in oneof which it does not actuate the latch lever and in the other of whichit is movable by the pitman to trip the latch lever, said bell cranklever in the first mentioned position being engageable by a wrist pin towhich the pitman is connected for moving the lever to the otherposition.

3. An automatic control mechanism for well rigs comprising a weightadapted for operative connection to the control element of a prime moverand adapted to actuate the control element to discontinue operation ofthe prime mover when the weight is released, means for latching theweight in an elevated position to prevent operation of the controlelement, actuating means for the latching means, and means for mountingthe actuating means for movement to occupy an inactive posltlon, and anactive position in which it actuates the latching means to release theweight.

4. An automatic control mechanism for well rigs comprising a weightadapted for operative connection to the control element of a prime moverand adapted to actuate the control element to discontinue operation ofthe prime mover when the weight is released, means for latching theweight in an elevated position to revent operation of the controlelement, an actuating means for the latching means comprising a pivotedmember normally occupying a position in which it is inefi'ective toactuate the latching means and capable of being moved to a secondposition in which it actuates the latching means to release the weight.

5. An automatic control mechanism for well rigs compriisng an upright, aweight movable on the upright, a cable connected to the weight andadapted for connection to the throttle valve of an engine, and a latchlever fulcrumed on the upright and havin a hooked portion engaging theweight w en the lever is in one position, to hold the weight in elevatedposition and prevent actuation of the throttle valve, the hooked portionbeing disengaged from the weight when the lever is moved to anotherposition to thereby render the weight free to gravitate and actuate thethrottle valve.

6. An automatic control mechanism for well rigs comprising an upright, aweight movable on the upright, a cable connected to the weight andadapted for connection to the throttle valve of an engine, and a latchlever pivoted on the upright above the weight and having a hookdepending therefrom engaging the weight when the lever is in oneposition, to hold the weight in elevated position and prevent actuationof the throttle valve, the hooked ortion being disengaged from theweight when the lever is moved to another position to thereby render theweight frtie to gravitate and actuate the throttle va ve.

FLOYD M. DETWILER.

